Roman “Ramon” Pacheco inserted himself into a scuffle that didn’t concern him at the now-former Mero’s Lounge in Dover and beat a bar patron to death with a metal stanchion before blithely stepping into a cab to go home, an assistant Morris County prosecutor argued Thursday.

While Assistant Prosecutor Matthew Troiano asked jurors in his opening statement to find that Pacheco murdered Edwin Alexander Chavez, 26, on March 21, 2011, defense lawyer Michael Fletcher argued that Pacheco did assault the victim but is not responsible for his death.

Troiano’s first trial witness — Dover resident Oscar Garnica — identified Pacheco in court as the man he saw strike Chavez twice in the chest with a metal stanchion that was part of the equipment used outside the East Blackwell Street nightclub for queuing up patrons.

“I just saw Roman come out with a post, the base of the post, and he struck him twice on the chest very hard. He got in a taxi like nothing happened and he left. He (Chavez) didn’t have a way to defend himself. He had nothing,” Garnica told the jury of nine women and six men hearing the trial before state Superior Court Judge Mary Gibbons Whipple in Morristown.

Before the taxi pulled away, Garnica said, he approached Pacheco, whom he knew as a street acquaintance.

“I was yelling at him. I was cursing at him because it wasn’t fair what he’d done,” Garnica testified through a Spanish-to-English interpreter.

The victim, a resident of Los Angeles, made his first trip to New Jersey in March 2011 with an uncle, Enrique Gonzales. After visiting a relative in Rockaway, they all decided to go dancing and drinking at Mero’s Lounge the night of March 20, 2011. Garnica also had gone to Mero’s that night.

Most of the night went smoothly until after midnight into March 21 when Chavez got into an argument with a bouncer and had to be forcibly removed by bouncers from the club. Troiano showed the jury portions of surveillance videotape from within the club that show bouncers muscling an agitated Chavez toward a door. The tape also shows Pacheco with his arm around Enrique Gonzales’ neck, leading him to a door.

Fletcher said that Pacheco, now 30, knew at least one member of Chavez’s group and was simply trying to help Gonzales get outside to safety. However, Troiano said that Pacheco inserted himself into a situation that didn’t concern him.

No surveillance cameras captured what occurred on the street outside Mero’s, but witnesses gave police accounts of what they observed, according to both Troiano and Fletcher. As he was being removed from the bar, Chavez tried to punch Pacheco but his fist grazed his face and hit bouncer Julian Mero instead. Mero went after Chavez and punched him, knocking him to the street, Troiano said.

Pacheco was right on Mero’s heels after he punched the victim and Pacheco followed up by lifting one of the metal stanchions and striking the victim twice in the chest while he lay motionless and unconscious on the ground. Pacheco then got into a cab and went to his home in Dover, Troiano said.

While Troiano said that Chavez died at 2:17 a.m. at Saint Clare’s Hospital in Dover of blunt force trauma to the chest, Fletcher said his client willingly told police he struck the victim in the stomach, not the chest. Fletcher said the victim was intoxicated with a blood alcohol content of .18 percent, and that other people and emergency workers “had contact” with Chavez’s chest while trying to medically assist him.

“Had Mr. Chavez taken his medicine like a man and let himself be taken out of the bar we wouldn’t be here,” Fletcher said.

Fletcher told jurors he wants them to find that Pacheco did not cause Chavez’s death. Troiano said he will prove that Pacheco committed murder by knowingly and purposefully causing serious bodily injury that resulted in death.

“When he picked up that metal stanchion, when he stood over a defenseless, motionless man and struck him, it was his objective to cause serious bodily injury that resulted in death,” Troiano said.

Jurors heard the name of bouncer Julian Mero but were not told that he will separately be tried for aggravated assault and endangering an injured victim. He is accused of punching the victim and rendering him unconscious but not of killing him.

During his interview with police after the death, Pacheco, who worked as a tree climber for a tree trimming company, said he brought his wife to Mero's to celebrate her birthday, and had two shots of tequila and a beer. He said his wife became intoxicated and he escorted her to the ladies room several times, running across Chavez who winked at his wife and grabbed her buttocks twice. Pacheco told the detectives the groping didn't faze him much but he was angered when Chavez tried to punch him while being thrown out of the bar by bouncers.